Which of the following reaction is possible ?

Options

A. `CH_3-Broverset(bar(O)H)rarr`
B. `CH_3OHoverset(Br^(-))rarr`
C.
D. `HC-=CHoverset(NaOH)rarr`

Answer

To determine which of the given reactions is possible, we will analyze each option step by step.

### Step 1: Analyze the first reaction: CH3Br + OH-
- **Reactants**: CH3Br (methyl bromide) and OH- (hydroxide ion).
- **Nature of OH-**: It is a strong base and a good nucleophile.
- **Nature of Br-**: Bromide ion (Br-) is a good leaving group.
- **Mechanism**: The hydroxide ion can attack the carbon atom bonded to bromine, leading to the displacement of Br-.
- **Products**: The reaction will yield CH3OH (methanol) and Br-.
- **Conclusion**: This reaction is possible.

### Step 2: Analyze the second reaction: CH3OH + Br-
- **Reactants**: CH3OH (methanol) and Br- (bromide ion).
- **Nature of OH-**: In this case, we are considering Br- as a nucleophile.
- **Mechanism**: Since OH- is a strong base and Br- is a weak base, Br- cannot displace OH- from methanol.
- **Conclusion**: This reaction is not possible.

### Step 3: Analyze the third reaction: C6H5Cl + OH-
- **Reactants**: C6H5Cl (aryl chloride) and OH- (hydroxide ion).
- **Nature of aryl halides**: Aryl halides do not undergo nucleophilic substitution reactions due to the stability of the aromatic ring.
- **Conclusion**: This reaction is not possible.

### Step 4: Analyze the fourth reaction: HC≡CH + NaOH
- **Reactants**: HC≡CH (acetylene) and NaOH (sodium hydroxide).
- **Nature of acetylene**: Acetylene is a very weak acid.
- **Mechanism**: Sodium hydroxide is a strong base but not strong enough to remove the hydrogen from acetylene.
- **Conclusion**: This reaction is also not possible.

### Final Conclusion:
After analyzing all four reactions, we find that only the first reaction (CH3Br + OH-) is possible.

### Summary of Possible Reaction:
- **Possible Reaction**: CH3Br + OH- → CH3OH + Br-
- **Correct Option**: The first reaction is the only possible reaction.

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